Oxyalkylate-sulfonate hydrocarbon inhibitor



United States Patent O 3,328,284 OXYALKYLATE-SULFONATE HYDROCARBON INHIBITOR Richard L. Godar, St. Louis, Mo., assignor to Petrolite Corporation, Wilmington, DeL, a corporation of Delaware No Drawing. Filed Jan. 6, 1965, Ser. No. 423,851 3 Claims. (Cl. 208-48) This application is a continuation of application Ser. No. 138,275 filed on Sept. 15, 1961 and is a continuation-in-part of application Ser. No. 138,276 filed on Sept. 15, 1961 all abandoned.

This invention relates to a method of chemically treating hydrocarbon liquids which contact surfaces under high temperature conditions in order to inhibit, prevent and/ or reduce the deposition of substances thereon. More specifically, this invention relates to the chemical treatment of the metal surfaces in contact with petroleum hydrocarbon liquids under conditions of high temperatures whereby said liquids tend to form deposits on such metal surfaces. This invention also relates to compositions employed in these processes.

In the processing of hydrocarbon liquids, particularly petroleum hydrocarbon liquids, elevated temperatures are often used in many necessary and important operations. To handle liquids at elevated temperatures, heat exchangers and the like devices are often employed to control the heat transfer rate from one operational step to another. When hydrocarbon liquids contact hot metal surfaces, there is sometimes a tendency for the liquid to decompose or undergo a chemical reaction that manifests itself in the form of deposits. These deposits may be either coke-like or they may be in the :form of tenacious, soft, sticky sludges which adhere to hot surfaces. Adherence of deposits, rather than deposit-formation itself is the essence of the problem, in contrast to fuel storage where residue in the oil itself creates the problem.

The problem is well recognized in the -artnote Petroleum Products Handbook, Guthrie (McGraW-Hill, 1960) pages 1-13, US. Patent 2,908,824 and elsewhere.

These deposits tend to materially decrease the heat transfer capacities of the metal surfaces and hence increase operating expenses. These deposits also require additional effort and time to remove andto restore the equipment to its original operating efliciency.

Petroleum refinery operations often encounter the above described conditions in many stages in the refining process. These deposits form on heat transfer surfaces at temperatures as low as about 200-225 F. and may be evidenced at temperatures as extreme as 800 F.

It is practically impossible to prevent these deposits by coating the metal surfaces with a protective permanent coating due to the possible loss of heat transfer. In addition, the large volume of liquid that contacts such equip- 3,328,284 Patented June 27, 1962 forming tendencies of said liquid whenit contacts metal ment increases the problem of treating metal surfaces in petroleum processing to prevent high temperature deposits.

It would be advantageous if a chemical agent could be added in an extremely small amount to a hydrocarbon liquid which tends to form high temperature deposits whereby such deposits would be prevented. It would also be desirable if such a chemical would not only prevent such deposits but would also remove them Without necessitating the stoppage of a given operation. It therefore becomes an object of the present invention to prevent the formation of high temperature deposits on metal surfaces by chemical means.

Another object is to furnish a chemical which when added to a hydrocarbon liquid will prevent the depositsurfaces at elevated temperatures.

A further object is to provide a chemical treatment which will prevent the formation of high temperature deposits by petroleum hydrocarbon liquids in contact with heat transfer equipment. 7 Yet another object is to furnish a chemical treatment capable of being combined with a thermally unstable, deposit-forming liquid whereby said liquid will not form deposits upon metal surfaces at elevated temperatures.

Still another object is to provide a chemical treatment which will remove high temperature deposits from metal surfaces of petroleum refining equipment without the necessity of stopping the operations of such equipment. Other objects will appear hereinafter.

In accomplishing these objects in accordance with the invention it has been found that new and improved resuits in preventing, inhibiting and/ or reducing the formation of deposits from petroleum hydrocarbon liquids during the processing thereof at elevated temperatures, particularly at temperatures within the range of about 200- 225 F. to 800 F., are obtained by adding to, preferably by dissolving or dispersing in the hydrocarbon liquid, the antifouling agent of this invention.

The anti-fouling compositions of this invention are synergistic mixtures of (1) oxyalkylated phenolic compounds and (2) organic sulfonates. Examples of the oxyalkylated phenolic compounds include the following:

wherein A is an alkylene group, for example etc., and is an aromatic moiety. These compounds are formed by oxyalkylating phenolic compounds by means of an alkylene oxide such as ethylene oxide, propylene .oxide, butylene oxide, etc. or mixturesthereof. In addition oxyalkylating with one alkylene oxide so as 'to form a homopolymer, and mixtures of alkylene oxides to form a heteropolymer, alkylene oxides may be added stepwise to form block polymers. I

For example, the following compounds can be'formed:

Homopolymer:

@ --(EtO),,Ol-[ (9 (PrO) OH (BuO),,OH

Heteropolymers:

The moieties may be derived from the following:

I O @OH, etc. R,

where R is a substituted group, for example, a hydrocarbon group such as an aryl radical, an alkoxy radical, an aliphatic radical, preferably alkyl, for example containing l-30 or more carbon atoms, such as 4-20 carbons, but preferably 8-18 carbons, A is an alkylene radical derived from an alkylene oxide such as ethylene, propylene, butylene, etc. oxides added singly, mixed, blocked, etc., n represents the number of moles of alkylene oxide for example 1 to 100 or more, such as 1-20, but preferably 1-10 and 2: represents the number of substituted groups, for example 1-2.

An example of an oil-soluble or dispersible polyoxyalkylene ether of an alkyl phenol is prepared by alkylating phenol with an olefin containing at least 6, and preferably 9 to 18, carbon atoms under conditions adapted to furnish an alkyl phenol reaction product having an average of l to 2 alkyl groups per phenol molecule. The olefins employed for the alkylation of phenol maybe straight-chain olefins, such as those produced in the Fischer-Tropsch synthesis; branched-chain olefins, such as those formed in the polymerization of propylene and butylene; or mixtures of branched-and straight-chain olefins which are recovered from a heavy cracked naphtha by selective adsorption with silica gel. Alcohols or alkyl chlorides with carbon chains of suitable length may be also employed as the alkylating agents. Preferably, mixture of C to C branched-chain olefins produced by polymerizing propylene are thus employed. The resulting alkyl phenol product which may contain from 15 to 20% by weight of dialkyl phenols, is condensed with ethylene oxide, propylene oxide, butylene oxide, individually or in combination, or a corresponding glycol. Ethylene oxide is usually preferred. Particularly suitable alkyl phenyl polyoxyalkylene ethers are alkyl phenyl polyoxyethylene ethers containing an average of 10-20 alkyl carbon atoms and l to 10 oxyethylene groups.

The organic sulfonate salts may be represented by the following formulae: (RSO Me, examples of which are petroleum sulfonate salts, alkyl aryl sulfonate salts, for example those of the formula (R Ar-SO Me, where Me represents a salt forming moiety, for example the elements of Group IA, Li, Na, K, etc., Group IIA, Mg, Ca, Sr, Ba, etc. of the periodic table, as Well as ammonium and amine salts thereof and 2 represents the number of sulfonate radicals which form the salt as determined by the valence of the metal forming the salt, for example where z is 1-2.

represents an aromatic group, for example,

phenyl, naphthyl, higher condensed aromatic systems, and R represents a substituted group, for example, a hydrocarbon group such as alkyl, and x represents the number of positions on the aromatic nucleus which are substituted. Further examples of alkyl aryl sulfonates are presented in the following table:

Table 1.-Ar0matic nucleus A. Benzene B. Toluene C. Xylenes, ethyl benzene, mesitylene, cymene, etc. D. Phenol E. Cresols, xylenols, and lower alkylated phenols F. Phenol ethers, anisole, phenetole, etc. G. Diaryl ethers, diphenyl ether, etc. H. Naphthalene I. Naphthols J. Naphthol ethers K. Diphenyl L. Phenyl phenols M. Diand triphenyl methanes N. Benzoins and desoxybenzoins O. Rosin and modified rosins Alkyl group Methyl and ethyl Propyl Butyl Amyl Hexyl Heptyl Straight chain octyl Octyl (Z-ethylhexyl) Octyl (diisobutyl) l0. Nonyls 11. Decyls 12. Keryls l3. Straight-chain alkyl C 14. Straight-chain hydroxylated or unsaturated alkyl, oleyl, ricinoleyl. These may be attached to one or more aromatic nuclei.

15. Mixed alkyl from cracked paraffin wax olefins 16. Mixed alkyl from polymers of C -C-, monoolefins 17. Mixed alkyl from naphthenes 18. Terpenoid, from terpene olefins or alcohols 19. Oleic acid derivative condensates, condensed through the double bond of the oleic chain 20. Acyl groups, i.e., alkyl aromatic ketones usually made by a Friedel-Orafts acylation reaction 21. Branched alkyl group derived from a ketone or aldehyde 22. Olefins from misc. synthetic processes 23. Steroid and complex alkyl-aromatic Sonneborn in its booklet Petroleum Sulfonates states that the generic formula of an oil petroleum soluble sulfonate is represented as [C H SO Me where Me is the metal of valence x and n is greater than 2-0.

The conditions encountered in refinery operations are simulated by exposing petroleum products taken from various refineries to high temperatures heat exchange tubes in the absence of and in the presence of the antifouling compositions of this invention.

A CFR fuel coker Model OlFC is employed to simulate these conditions. It is described in CR'C Manual No. 3, March 1957, published by the Coordinating Fuel and Equipment Research Committee of the Coordinating Research Council, Inc. The standard procedure is employed except that the equipment is modified so as to bypass the filter section.

The conditions of the test are as follows:

Test time-3O minutes Test temperature-575 F. Test pressure-J50 p.s.i. Test rate of flow-'3 lbs./hr.

The amount of fouling which occurs is measured by observing the preheater (or heat exchanger) tube before and after the test to determine the amount of deposits formed on the preheater tube. One finds the appearance of the preheater tube to correspond with the amounts of fouling measured by gravimetric means, Gravimetric results generally corroborate the results obtained by inspection of the tube. Thus, the tenn s employed in the table have the following meaning:

Heavy-8-12 mg. of residue Moderately heavy-6-8 mg. of residue Moderate4-6 mg. of residue Light--2-4 mg. of residue Very lightless than 2 mg. of residue be taken into consideration such as whether large amounts will have any adverse effects on present or subsequent Table 11 Ex. Additive P.p.m. Test Fouling Deposit on Exchange Employed per Min. Tube 30 Heavy fouling. Commercial Composition A" 30 Light fouling. Commercial Composition BE. 45 Do. Commercial Composition A* 30 Do. Commercial Composition Ch- 50 30 Do. Commercial Composition D* 50 30 Do. Commercial Composition E* 50 30 Do. Oil soluble mixture of Ba, 50% Ca and 3O Mod. heavy fouling. Na petroleum sulionates. 9 Dinonyl phenol+l0 moles 'EtO 38 30 Do. I 10 8+9 (weight ratio of 8 to 9 is 2:3) 30 30 Substantially no fouling.

*The commercial compositions A, B, C, D and E shown in the above table are oil soluble blends of oxyethylated nlkylphenols and sodium petroleum sulfonate sal ts.

All of the above petroleum sulfonates can be described by the general formula [C H SO Me, where Me is a metal of valence x, and n is greater than 20.

The effective ratio of oxyalkylated phenol to organic sulfonate salts can vary widely depending on many variables such as the specific compounds employed the specific systems, specific temperatures, etc. In general, an effective amount of each is employed, for example the ratio of oxyalkylated phenol to organic sulfonate can vary from about 0.5 :10 to 10:0.5, such as about 1:4 to 4:1 but preferably about 2:3 to 32 2.

The above tests are typical of the screening tests employed in evaluating anti-fouling additives. After being screened in this manner, the anti-fouling additives are employed in petroleum refinery operations. By means of the above tests, the most effective additive is selected from the particular hydrocarbon under consideration and the additive is then employed in the specific operation.

The anti-fouling additive can be employed in refining crude petroleum as well as in the treatment of any component thereof which are exposed to high temperatures including the light distillates, for example light naphthas,

intermediate naphthas, heavy naphthas, etc.; middle distillates, for example kerosene, gas oil, etc.; distillate lube oil stocks, for example, white oil, saturating oil, light lube oil, medium lube oil, heavy lube oil, and the like.

In addition, the additive can be employed with other hydrocarbons such as xylene, benzene, purified hydrocarbon compounds, etc. In addition, they can be employed under certain conditions with non-hydrocarbons, such as alcohols, phenols, etc. For example, they can be employed in a toluene extraction tower and stripper which process comprises mixing phenol and toluene in an extraction whereby phenol extracts impurities from toluene and the raffinate is subsequently removed. Thereafter the mixture is sent to a stripper where the toluene is removed from the phenol by distillation. The remaining phenol is recycled to the extractor for further use. The system is 0perated over a wide temperature range for example 230- 425 F. Deposits in the phenol circuit cause the loss of excessive amounts of phenol. It can be used in heat transfer units used in a furfurol extraction process for example, intermediate distillates, paraffin distillates, decanted oil, vacuum cylinder stock, deasphalted cylinder stock, etc.

The amount of anti-fouling agent required in this invention is subject to wide variation but in general very effective results have been obtained by adding relatively minute amounts of the anti-fouling agent to the hydrooperations. Because of the many. different types of operations where hydrocarbons are heated to elevated temperatures under conditions where-deposits are formed, it is difficult to give specific ranges which will be effective in all operations. The amount of agent which-inhibits the formation of deposits is referred to hereinas an antifouling amoun The above figures relate to p.p.m. in terms of active anti-fouling chemical not including the solvent employed, and includes both the oxyalkylated phenol and the organicsulfonates.

Inasmuch as the anti-fouling agent is employed in such small 1 amounts and it is preferable to feed them continuously or semi-continuously by means of a proportioning pump or other suitable device to the particular hydrocarbon liquid being processed or to add them in a similar manner to the apparatus in which the hydrocarbon liquid is being processed, it is desirable to incorporate the agent or a mixture of agents intoa suitable solvent which will be compatible with the liquid which is to be processed. The solvent which is used to dissolve the active ingredient also. subject to some variation depending upon the solubility characteristics of the particular compound employed. In some cases, even though the active mixture is insoluble in a particular solvent, it will dissolve in a combination of solvents.

In the practice of the invention it is very desirable to start the treatment with the chemicalsemployed for the purpose of the invention at a higher dosage, say 50 to p.p.m. or more of a composition and then gradually reduce the dosage to the point where fouling of the apparatus is just eliminated.

The invention is especially valuable where sour naphthas are being processed or where the oil being processed is a mixture containing some .sour naphthas.

Examples of specific types of apparatus to which the chemical compositions of the invention f can be added during petroleum processing are fractioning towers, stripping columns, debutanizers, depropanizers, deethanizers, heat exchangers, reboilers, hot product lines and other metal equipment (usually ferrous metal) which is brought into contact with the organic liquids being processed at relatively high temperatures. The invention makes it possible to extend the useful life of crude oil fractionating towers and other types of petroleum refinery equipment. It also makes it possible to provide cleaner inside surfaces resulting in better fractionation, better heat exchange in coolers, far less severe plugging and less time required for cleaning and maintenance.

Having thus described my invention what I claim as new and desire to obtain by Letters Patent is:

1. A process for inhibiting in oil refining apparatus during petroleum refining operations the formation of adherent coke-like deposits and adherent tenacious soft, sticky sludges on, and the adhesion of said deposits and said sludges to, the hot metal heat transfer surfaces of a heat exchanger in said oil refining apparatus by a thermally unstable hydrocarbon liquid, said hydrocarbon liquid having the tendency to undergo a chemical reaction at a temperature in the range of about 225 F. to about 800 F., said chemical reaction manifesting itself in the form of adherent coke-like deposits and adherent soft, sticky sludges, such as are usually formed during passage of said hydrocarbon liquid through said heat exchanger and in contact with the hot metal surfaces of said heat exchanger in said oil refining apparatus at a temperature in the range of about 225 F. to about 800 F. comprising (1) incorporating in said hydrocarbon liquid prior to contact with said metal surfaces of said heat exchanger in said oil refining apparatus an anti-fouling amount of a composition comprising (A) an oxyalkylated phenolic compound selected from the group consisting of and (OAMOH wherein A is an alkylene group having at wherein Me is a metal of valence x,

x is an integer of 1-2, and n is an integer greater than 20,

(2) mixtures of petroleum sulfonate salts, each having the general formula of said salt (1) and Me of each being different, and

(3) an alkyl aryl sulfonate salt having the formula (R ArSO Me wherein Me is a metal of valence z,

z is an integer of 1-2, Ar is an aromatic radical, R is a hydrocarbon-containing radical having l-18 carbon atoms, and x is an integer of 1-3, representing the number of nuclear substituted groups on said aromatic radical the weight ratio of A to B ranging from the ratio of 0.5:10 to the ratio of 1020.5 and (2) heating said hydrocarbon liquid having incorporated therein said composition in an antifouling amount to a temperature in the range of about 225 F. to about 800 F. by contact with said hot metal surfaces of said heat exchanger in said oil refining apparatus. 2. The process of claim 1 wherein the oxyalkylated phenolic compound is 0 11 and the organic sulfonate salt is an alkyl aryl sulfonate salt having the formula BIO; Me

wherein Me is a metal having a valence of I2 and R is an alkyl radical having 1-18 carbon atoms, and the weight ratio of said oxyalkylated phenolic compound to said organic salt is 3:2.

3. The process of claim 1 wherein the oxyalkylated phenolic compound is and the organic sulfonate salt is a mixture of 20% Ba, 50% Ca and 30% Na petroleum sulfonates, and the weight ratio of said oxyalkylated phenolic compound to said mixture is 3:2.

References Cited UNITED STATES PATENTS 2,485,150 10/ 1949 Glavis et a] 25252 3,105,810 10/1963 Miller et a1 208-48 FOREIGN PATENTS 569,230 1/1959 Canada.

DELBERT E. GANTZ, Primary Examiner.

PAUL M. COUGHLAN, Examiner.

A. RIMENS, Assistant Examiner. 

1. A PROCESS FOR INHIBITING IN OIL REFINING APPARATUS DURING PETROLEUM REFINING OPERATIONS THE FORMATION OF ADHERENT COKE-LIKE DEPOSITS AND ADHERENT TENACIOUS SOFT, STICKY SLUDGES ON, AND THE ADHESION OF SAID DEPOSITS AND SAID SLUDGES TO, THE HOT METAL HEAT TRANSFER SURFACES OF A HEAT EXCHANGER IN SAID OIL REFINING APPARATUS BY A THERMALLY UNSTABLE HYDROCARBON LIQUID, SAID HYDROCARBON LIQUID HAVING THE TENDENCY TO UNDERGO A CHEMICAL REACTION AT A TEMPERATURE IN THE RANGE OF ABOUT 225*F. TO ABOUT 800*F., SAID CHEMICAL REACTION MANIFESTING ITSELF IN THE FORM OF ADHERENT COKE-LIKE DEPOSITS AND ADHERENT SOFT, STICKY SLUDGES, SUCH AS ARE USUALLY FORMED DURING PASSAGE OF SAID HYDROCARBON LIQUID THROUGH SAID HEAT EXCHANGER AND IN CONTACT WITH THE HOT METAL SURFACES OF SAID HEAT EXCHANGER IN SAID OIL REFINING APPARATUS AT A TEMPERATURE IN THE RANGE OF ABOUT 225*F. TO ABOUT 800*F. COMPRISING (1) INCORPORATING IN SAID HYDROCARBON LIQUID PRIOR TO CONTACT WITH SAID METAL SURFACES OF SAID HEAT EXCHANGER IN SAID OIL REFINING APPARATUS AN ANTI-FOULING AMOUNT OF A COMPOSITION COMPRISING (A) AN OXYALKYLATED PHENOLIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF 